The C1-A55 from RD Microwaves is a Directional Coupler with Frequency 698 MHz to 2.8 GHz, Coupling 10 dB, Coupling Variation ±0.5 dB, Directivity 17 to 20 dB, Average Power 100 W. Tags: Module with Connectors. More details for C1-A55 can be seen below.